Camshafts and Camshaft Cases

GENERAL 151-1

Special tools 151-1

CAMSHAFTS 151-1

Camshafts, removing and installing 151-1

Camshaft specifications 151-8

CAMSHAFT CASES 151-9

Oil spray tube, replacing 151-9

TABLES

a. Camshaft and Valvetrain Clearances 151-8

Special Tools

Special tool

A 9191 Cam sprocket counterholding wrench

(Porsche ordering #000 721 919 10)

B P 212 Camshaft sprocket lockpin extractor

(Porsche ordering #000 721 212 00)

C P 213 b Feeler gauge

(Porsche ordering #000 721 213 20)

Battery electrolyte Is a corrosive acid. Always wear eye protection when working on or near the battery.

GENERAL

This section covers information and repairs to the camshaft cases, camshafts, rocker shafts and rocker arms. Engine disassembly, including camshaft and camshaft case removal, is covered in 102 Engine Disassembly and Assembly.

Timing chain replacement or adjustment is covered in 152 Camshaft Timing Chains.

Special tools

Some of the procedures require special tools.

CAMSHAFTS

Camshafts and rocker shafts can be removed from the camshaft cases with the engine installed.

Camshafts, removing and installing

— Raise car and support in a safe manner.

Make sure the car is stable and well supported at all times. Use a professional automotive lift or jack stands designed for the purpose. A floor jack is not adequate support.

— Disconnect negative (-) battery cable and cover battery terminal to keep cable from accidentally contacting terminal.

Negative Camber Adjustment Porsche 911

— Remove intake and exhaust valve covers on both sides.

^ Loosen cylinder 1 valve adjuster lock nuts and fully back out valve adjusting screws.

— Remove muffler as described in 260 Exhaust System. Remove rear engine metal shroud.

Set crankshaft to Z1 cylinder 1 compression TDC (arrow).

At cylinder 1 TDC, the intake and exhaust valves for cylinder 1 will be closed.

^ Counterhold cylinder 1 intake rocker shaft nut with 8 mm alien wrench and loosen other end with 5 mm alien wrench.

Mark location of each rocker arm. Do not interchange used parts.

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0018304

0018306

^ Tap rocker shaft out, removing rocker arm.

— Turn crankshaft 120° in normal direction of rotation. Remove cylinder 6 rocker shafts and arms.

— Following firing order, turn crankshaft 120° and remove rocker shafts and arms for next cylinder. Repeat until all rocker shafts and arms are removed.

^ Remove left timing chain tensioner oil feed line (A).

• Remove left camshaft housing oil feed line (B).

• Remove left timing chain housing cover.

^ Loosen left camshaft sprocket mounting bolt. NOTE —

Use Porsche special tool 9191 or equivalent to counterhold camshaft sprocket when loosening bolt.

001S78S

Porsche 911 Firing Order

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Porsche Rocker Shaft Removal

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Compress timing chain tensioner using large pliers.

• Install 3 mm (1/8 in.) pin through hole in upper tensioner body (arrow) to lock tensioner down.

Check position of timing chain tensioner piston in its installed position. If piston is fully extended, the timing chains and sprockets are most likely worn. See 152 Camshaft Timing Chains.

^ Remove timing chain tensioner (A) and idler sprocket assembly (B).

• Remove camshaft sprocket bolt from left camshaft (C).

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Lockpin Images

^ Remove camshaft sprocket lockpin using Porsche special tool P 212 or equivalent.

— Remove camshaft sprocket and disengage from timing chain.

— Remove camshaft sprocket flange.

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10. Sealing O-ring

11. Gasket

12. Camshaft

13. Woodruff key

Camshaft and cover retaining bolt Sprocket spacer shims Thrust spacer Camshaft end cover

1. Sprocket mounting bolt 6.

2. Lock washer

3. Sprocket lockpin 7.

4. Camshaft sprocket 8.

5. Sprocket flange 9.

Camshaft sprocket assembly

10. Sealing O-ring

11. Gasket

12. Camshaft

13. Woodruff key

Camshaft and cover retaining bolt Sprocket spacer shims Thrust spacer Camshaft end cover

1. Sprocket mounting bolt 6.

2. Lock washer

3. Sprocket lockpin 7.

4. Camshaft sprocket 8.

5. Sprocket flange 9.

Camshaft End Thrust

Remove left camshaft:

• Remove woodruff key (A) from camshaft.

• Remove camshaft end cover retaining bolts (arrows).

• Remove camshaft end cover (B), shims and thrust spacer.

• Slide camshaft toward pulley end of engine to remove.

• Wire tie end cover, shims and thrust spacer together and label.

• For identification, the left camshaft is marked "147-10" on the end.

— Repeat procedures on right side camshaft. NOTE —

For identification, the right camshaft is marked "148-10" on the end.

— To reinstall, slide left camshaft into camshaft case.

• Install camshaft end cover with new O-ring and gasket.

• Install camshaft and cover retaining bolts and tighten.

— Reinstall left side cam sprocket spacer shims, woodruff key and camshaft sprocket flange.

— Put left timing chain over camshaft sprocket.

• Slide sprocket and lock washer over sprocket flange.

• Install sprocket mounting bolt finger tight.

— Install right camshaft, camshaft sprocket assembly and timing chain as described in previous steps.

Camshaft sprocket orientation

Camshaft sprocket orientation

Left and right camshaft sprockets are identical. Dished side of sprocket must face pulley side of engine on left camshaft (cylinders 1 - 3) and flywheel side of engine on right camshaft (cylinders 4 - 6).

— Check that cam sprockets run parallel with intermediate shaft sprocket. See 152 Camshaft Timing Chains.

Myvi Timing Chain Mark

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• Under most normal circumstances, if reinstalling previously used camshafts and sprockets, 3 sprocket spacer shims will be necessary under the left sprocket and 4 shims under the right sprocket.

' If new camshafts or sprockets are being installed, check to make sure that the sprockets are running parallel to each other to minimize chain wear. See 152 Camshaft Timing Chains.

— Install left timing chain tensioner and idler sprocket assembly.

• Remove locking cotter pin from chain tensioner, if applicable.

^ Set crankshaft to Z1. Make sure it is at cylinder 1 compression TDC by aligning distributor rotor with scribe mark on distributor housing (arrows).

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Porsche 911 Rocker Arm Shaft

Be sure to set fine camshaft timing as described in 152 Camshaft Timing Chains.

^ Turn camshafts so that "930" marks point up.

— For initial timing adjustment:

• Remove left camshaft sprocket mounting bolt and lock washer.

• In this position one hole in camshaft sprocket will be aligned with one hole in sprocket flange. Insert camshaft sprocket lockpin.

• Reinstall sprocket retaining bolt finger tight.

— Repeat initial timing procedures for right camshaft.

— Turn crankshaft clockwise two full turns and recheck initial timing.

Porsche 911 Cylinder Sleeves

Rocker shaft assembly

0018305

1. Pinch bolt (5 mm alien) 4. Rocker arm

2. Expansion sleeve 5. Expansion nut (8mm

3. Rocker shaft alien)

Rocker shaft assembly

0018305

1. Pinch bolt (5 mm alien) 4. Rocker arm

2. Expansion sleeve 5. Expansion nut (8mm

3. Rocker shaft alien)

^ Install rocker shafts and arms for each cylinder with camshafts set for TDC compression for that cylinder.

• Install cylinder 1 and 3 rocker shafts with 5 mm alien bolt facing cylinder 2.

• Install cylinder 4 and 6 rocker arms with 5 mm bolt facing cylinder 5.

• Cylinder 2 and 5 rocker shaft can be installed either way.

— Tap rocker shaft into bore until shaft is flush with inner edge of support.

— Place rocker arm in position and tap rocker shaft in until shaft slides into far side support.

Porsche 911 Rocker Arm Shaft

^ Tap rocker arm shaft into position so that shaft is centered in camshaft housing.

• Tighten rocker arm shaft pinch bolt.

Tightening Torque

— Torque camshaft sprocket bolts. NOTE —

Use Porsche special tool 9191 or equivalent to counterhold camshaft sprocket when torquing bolt.

Tightening Torque

• Chain sprocket to camshaft 120 Nm (89 ft-lb)

Adjust all intake and exhaust valves to 0.1 mm (0.004 in.) as described in 030 Maintenance.

— Install valve covers with new gaskets, sealing washers and new lock nuts.

Tightening Torque

• Valve cover to camshaft case (always replace) 8 Nm (71 in-lb)

— Install timing chain housing covers with new gaskets, sealing washers and lock nuts.

— Install right and left camshaft oil feed lines with new sealing washers.

Camshaft timing values

4 before :

4 before :

Porsche Fastener Torque Chart

Tightening Torque

• Chain housing cover to housing 8 Nm (89 in-lb)

— Install right and left timing chain tensioner oil feed lines with new sealing washers.

— Install rear engine metal shroud.

— Install muffler, using a new gasket and hardware.

Camshaft specifications

^ Stock camshaft timing values are given below.

Camshaft Valve Timing

• Exhaust closes At TDC

Camshaft and valve train specifications are given in Table a. Table a. Camshaft and Valvetrain Clearances

Measuring point

Tolerance

Wear limit

Camshaft bearing bore

48.967 - 48.992 mm (1.9278- 1.9288 in.)

0.10 mm (0.004 in.)

Camshaft journal

48.926 - 48.942 mm (1.9262- 1.9268 in.)

0.10 mm (0.004 in.)

Camshaft run-out

0.02 mm (0.0007 in.)

Rocker arm shaft bearing bore

17.992-18.000 mm (0.7083 - 0.7086 in.)

Rocker arm shaft

18.000-18.018 mm (0.7086 - 0.7093 in.)

Rocker arm bore

18.000-18.018 mm (0.7086 - 0.7093 in.)

0.080 mm (0.003 in.)

CAMSHAFT CASES

The camshaft cases can only be removed with the engine out of the vehicle. See 102 Engine Disassembly and Assembly.

Oil spray tube, replacing

The left and right camshaft cases each contain an oil spray tube for valvetrain lubrication. On high mileage engines and engines that have had catastrophic bearing failure, the tubes should be removed and cleaned prior to engine assembly.

^ With camshaft case removed and cleaned, blow compressed air in each camshaft tower oil feed line hole. Check each oil spray tube orifice (arrows) for air flow.

If a blocked hole is found, drill 5 mm (0.2 in.) hole approximately 9 mm (0.35 in.) deep in oil passage plug (arrow).

• Using an M6 tap, thread drilled hole.

• Remove oil spray tube and clean thoroughly.

• Reinstall tube and replace end plug.

Oil spray tubes must always be removed and cleaned thoroughly when engine bearings have failed.

1984 Porsche 911 Oil Line

00.18709

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Responses

  • ennio
    Can porsche 911 cam towers rocker bores be restored?
    1 year ago
  • tesfalem
    How to tell left from right camshaft?
    5 months ago

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